Multilayer ceramic electronic component

ABSTRACT

The multilayer ceramic electronic component includes a ceramic body including a dielectric layer; and first and second internal electrodes disposed inside the ceramic body, and disposed to oppose each other with the dielectric layer interposed therebetween. When an average thickness of the dielectric layer is referred to as td and a standard deviation of a thickness of the dielectric layer in each position is referred to as σtd, while an average thickness of the first and second internal electrodes is referred to as to and a standard deviation of a thickness of a pre-determined region of any layer of the internal electrodes in each position is referred to as σte, a ratio (σte/σtd) of the standard deviation of the internal electrodes in each position to the standard deviation of the thickness of the dielectric layer in each position satisfies 1.10≤σte/σtd≤1.35.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application claims the benefit of priority to Korean PatentApplication No. 10-2019-0094257 filed on Aug. 2, 2019 in the KoreanIntellectual Property Office, the disclosure of which is incorporatedherein by reference in its entirety.

TECHNICAL FIELD

The present disclosure relates to a multilayer ceramic electroniccomponent, and more specifically to a multilayer ceramic electroniccomponent having excellent reliability and a manufacturing methodthereof.

BACKGROUND

Generally, electronic components using ceramic materials such ascapacitors, inductors, piezoelectric devices, varistors, thermistors, orthe like, may include a ceramic body formed of a ceramic material,internal electrodes formed inside the ceramic body, and externalelectrodes disposed on a surface of the ceramic body so as to beconnected to the internal electrodes.

Among multilayer ceramic electronic components, a multilayer ceramiccapacitor includes a plurality of laminated dielectric layers, internalelectrodes disposed to oppose each other with a dielectric layerinterposed therebetween, and external electrodes electrically connectedto the internal electrodes.

Multilayer ceramic capacitors are widely used as components ofcomputers, PDAs, mobile phones, and other mobile communication devicesdue to their small size, high capacity and ease of mounting.

Recently, in accordance with the lightening and miniaturization ofelectronic devices with high performance, there has been demand also forelectronic components to be miniaturized and have high performance andhigh capacity.

In particular, a method of simultaneously achieving miniaturization,high performance and high capacity is to laminate a large number oflayers by reducing thicknesses of dielectric layers and the internalelectrode layers of the multilayer ceramic capacitor. Currently, thethickness of the dielectric layer has reached at about 0.6 μm, andslimming of the dielectric layers is ongoing.

In this regard, a ratio of interface contact between the internalelectrode and the dielectric continuously increases; however, a regionin which a metal and ceramic are bonded is vulnerable to delaminationand cracking due to low adhesion therebetween.

As the delamination and cracking lead to deterioration of moistureresistance reliability of the multilayer ceramic capacitor, a new methodfor securing high reliability with respect to materials or structures tosolve such problems.

SUMMARY

The present disclosure relates to a multilayer ceramic electroniccomponent and a manufacturing method thereof, and more particularly to amultilayer ceramic electronic component and a manufacturing methodthereof having excellent reliability.

According to an aspect of the present disclosure, a multilayer ceramicelectronic component includes a ceramic body including a dielectriclayer; and first and second internal electrodes disposed inside theceramic body, and disposed to oppose each other with the dielectriclayer interposed therebetween, wherein, when an average thickness of thedielectric layer is referred to as td and a standard deviation of athickness of the dielectric layer in each position is referred to asσtd, while an average thickness of the first and second internalelectrodes is referred to as to and a standard deviation of a thicknessof a pre-determined region of any layer of the internal electrodes ineach position is referred to as σte, a ratio (σte/σtd) of the standarddeviation of the internal electrodes in each position to the standarddeviation of the thickness of the dielectric layer in each positionsatisfies 1.10≤σte/σtd≤1.35.

According to another aspect of the present disclosure, a manufacturingmethod of a multilayer ceramic electronic component includes preparing aceramic green sheet comprising ceramic powder, forming an internalelectrode pattern with a conductive paste comprising a conductive metalparticle and an additive on the ceramic green sheet, laminating aceramic green sheet on which the internal electrode pattern is formed toform a ceramic laminate and plasticizing the ceramic laminate to form aceramic body comprising a dielectric layer and an internal electrode,wherein, when an average thickness of the dielectric layer is referredto as td and a standard deviation of a thickness of the dielectric layerin each position is referred to as σtd, while an average thickness ofthe first and second internal electrodes is referred to as to and astandard deviation of a thickness of a pre-determined region of anylayer of the internal electrodes in each position is referred to as σte,a ratio (σte/σtd) of the standard deviation of the internal electrodesin each position to the standard deviation of the thickness of thedielectric layer in each position satisfies 1.10≤σte/σtd≤1.35.

BRIEF DESCRIPTION OF DRAWINGS

The above and other aspects, features, and advantages of the presentdisclosure will be more clearly understood from the following detaileddescription taken in conjunction with the accompanying drawings, inwhich:

FIG. 1 is a schematic perspective view illustrating a multilayer ceramiccapacitor according to an exemplary embodiment of the presentdisclosure;

FIG. 2 is a schematic cross-sectional view illustrating a multilayerceramic capacitor taken along line I-I′ of FIG. 1;

FIG. 3 is an enlarged view of region “A” of FIG. 2; and

FIG. 4 is an enlarged view of region “B” of FIG. 3.

DETAILED DESCRIPTION

Hereinafter, exemplary embodiments of the present disclosure will now bedescribed in detail with reference to the accompanying drawings. Thepresent disclosure may, however, be exemplified in many different formsand should not be construed as being limited to the specific exemplaryembodiments set forth herein. Rather, these exemplary embodiments areprovided so that this disclosure will be thorough and complete, and willfully convey the scope of the disclosure to those skilled in the art. Inthe drawings, the shapes and dimensions of elements may be exaggeratedfor clarity. Further, in the drawings, elements having the samefunctions within the same scope of the inventive concept will bedesignated by the same reference numerals.

An exemplary embodiment of the present disclosure relates to a ceramicelectronic component. The electronic component using the ceramicmaterial includes a capacitor, an inductor, a piezoelectric element, avaristor, a thermistor, or the like. Hereinafter, a multilayer ceramiccapacitor will be described as an example of the ceramic electroniccomponent.

FIG. 1 is a schematic perspective view illustrating a multilayer ceramiccapacitor according to an exemplary embodiment of the presentdisclosure.

FIG. 2 is a schematic cross-sectional view illustrating a multilayerceramic capacitor taken along line I-I′ of FIG. 1.

FIG. 3 is an enlarged view of region “A” of FIG. 2.

FIG. 4 is an enlarged view of region “B” of FIG. 3.

Referring to FIGS. 1 to 4, a multilayer ceramic capacitor according toan exemplary embodiment of the present disclosure may include a ceramicbody 110, internal electrodes 121 and 122 formed inside the ceramicbody, and external electrodes 131 and 132 formed on outside of theceramic body 110.

In an exemplary embodiment, the “length direction,” “width direction,”and “thickness direction” of FIG. 1 are defined as an “L” direction, a“W” direction, and a “T” direction. The “thickness direction” may beused in the same sense as a direction in which the dielectric layers arelaminated up, for example, a “lamination direction.”

Although not particularly limited, the ceramic body 110 according to anexemplary embodiment may have a rectangular cuboid shape.

The ceramic body 110 may be formed by laminating a plurality ofdielectric layers 111.

A plurality of the dielectric layers 111 constituting the ceramic body110, in a sintered state, may be integrated in a single body such thatboundaries between adjacent dielectric layers 111 may not be readilyapparent.

The dielectric layer 111 may be formed by sintering a ceramic greensheet containing ceramic powder.

The ceramic powder is not particularly limited as long as it isconventionally used in the art.

Although not limited thereto, the ceramic powder may contain, forexample, BaTiO₃-based ceramic powder.

The BaTiO₃-based ceramic powder may be (Ba_(1−x)Ca_(x))TiO₃,Ba(Ti_(1−y)Ca_(y))O₃, (Ba_(1−x)Ca_(x))(Ti_(1−y)Zr_(y))O₃ orBa(Ti_(1−y)Zr_(y))O₃, or the like, in which calcium (Ca), zirconium(Zr), or the like, is included in BaTiO₃, but is not limited thereto.

In addition to the ceramic powder, the ceramic green sheet may contain atransition metal, a rare-earth element, magnesium (Mg), aluminum (Al),or the like.

A thickness of the dielectric layer 111 may be appropriately changedaccording to capacitance design of the multilayer ceramic capacitor.

For example, the thickness of the dielectric layer 111 formed betweentwo adjacent internal electrode layers after sintering may be 0.4 μm orless, but is not limited thereto.

In an exemplary embodiment of the present disclosure, the thickness ofthe dielectric layer 111 may refer to an average thickness.

The average thickness of the dielectric layer 111 is an averagethickness of the ceramic body 110 in a length-thickness (L-T) directioncross-section cut in a central portion in a width (W) direction thereof.

The average thickness of the dielectric layer 111 may be measured byscanning an image of the ceramic body 110 in the length directioncross-section with a scanning electron microscope (SEM), as illustratedin FIG. 2.

For example, an average value may be calculated by measuring thicknessesof any dielectric layer extracted from an SEM-scanned image of theceramic body 110 whose length-thickness (L-T) direction cross-section iscut in a central portion in the width direction (W) at 30 positions atan equidistant interval in the length direction.

The 30 positions at an equidistant interval may be measured at acapacitance formation portion, a region in which the internal electrodes121 and 122 overlap.

In addition, when an average value is measured for at least 10dielectric layers, thereby increasing a measurement scale, the averagethickness of the dielectric layer may be further generalized.

The internal electrodes 121 and 122 may be disposed inside the ceramicbody 110.

The internal electrodes 121 and 122 may be formed and laminated on theceramic green sheet, and may be formed inside the ceramic body 110 bysintering with one dielectric layer interposed therebetween.

The internal electrode may be a pair of first and second internalelectrodes 121 and 122 having different polarities, and may be disposedto oppose each other in the lamination direction of the dielectriclayer.

As illustrated in FIG. 2, ends of the first and second internalelectrodes 121 and 122 may be alternately exposed to one surface of theceramic body 110 in the longitudinal direction.

In addition, although not illustrated, the first and second internalelectrodes according to an exemplary embodiment of the presentdisclosure may have lead portions, and may be exposed to the samesurface of the ceramic body through the lead portions. Alternately, thefirst and second internal electrodes may have lead portions, and may beexposed to one or more surfaces of the ceramic body through the leadportions.

Although not particularly limited, a thickness of the first and secondinternal electrodes 121 and 122 may be, for example, 0.41 μm or less.

According to an exemplary embodiment of the present disclosure, 200 ormore dielectric layers on which the internal electrodes are formed maybe laminated.

According to an exemplary embodiment, when the thickness of the firstand second internal electrodes 121 and 122 is 0.41 μm or less, moistureresistance reliability may be improved. Even in the case of thin filminternal electrodes, a featured constitution, excellent withstandvoltage, may be achieved. When the thickness of the first and secondinternal electrodes 121 and 122 exceeds 0.41 μm, withstand voltage ordeteriorations of reliability may not occur even when the featuredconstitution of the present disclosure is not applied.

In other words, the following featured constitution of the presentdisclosure may be applied to improve reliability when the thickness ofthe first and second internal electrodes 121 and 122 is 0.41 μm or less.

The average thickness of the first and second internal electrodes 121and 122 is an average thickness in the length-thickness (L-T) directioncross-section of the ceramic body 110 cut in a central portion in thewidth direction (W).

According to an exemplary embodiment, external electrodes 131 and 132may be formed on an exterior of the ceramic body 110 and may beelectrically connected to the internal electrodes 121 and 122.

More specifically, the external electrodes 131 and 132 may be configuredto have the first external electrode 131 electrically connected to thefirst internal electrode 121 exposed to one surface of the ceramic body110 and the second external electrode 132 electrically connected to thesecond internal electrode 122 exposed to the other surface of theceramic body 110.

In addition, a plurality of the external electrodes may be formed to beconnected to the first and second internal electrodes exposed to theceramic body.

The external electrodes 131 and 132 may be formed of a conductive pastecontaining metal powder.

The metal powder contained in the conductive paste is not particularlylimited, and may be, for example, nickel (Ni), copper (Cu) or alloysthereof.

A thickness of the external electrodes 131 and 132 may be appropriatelydetermined depending on a purpose, or the like, and may be, for example,about 10 μm to 50 μm.

Referring to FIGS. 3 and 4, with respect to a multilayer ceramicelectronic component according to an exemplary embodiment, when anaverage thickness of the dielectric layer is referred to as td and astandard deviation of a thickness of the dielectric layer in eachposition is referred to as σtd, while an average thickness of the firstand second internal electrodes is referred to as to and a standarddeviation of a thickness of a pre-determined region of any layer of theinternal electrodes in each position is referred to as σte, a ratio(σte/σtd) of the standard deviation of the internal electrodes in eachposition to the standard deviation of the thickness of the dielectriclayer in each position satisfies 1.10≤σte/σtd≤1.35.

In recent years, most cases of the moisture resistance deteriorations ofreliability in highly laminated multilayer ceramic capacitors with highcapacity are mainly caused by delamination and cracking due to weakeningof the adhesion between the metal and the ceramic at an interfacebetween the internal electrode and the dielectric.

In order to solve the problem of moisture resistance deteriorations ofreliability of the multilayer ceramic capacitor, it is necessary toincrease an interfacial adhesion between the internal electrode and thedielectric. If a surface area of an interfacial bonding area increases,the deterioration of moisture resistance may be resolved.

In addition, the surface area of the interfacial bonding area betweenthe internal electrode and the dielectric may be increased by finelyadjusting roughness of the internal electrode.

However, excessive adjustment of a roughness profile of the internalelectrode may give rise to a side effect of reduced withstand voltagecharacteristics of the multilayer ceramic capacitor. Accordingly, it isnecessary to appropriately adjust the roughness of the internalelectrode to improve the withstand voltage in addition to the moistureresistance reliability.

According to an exemplary embodiment of the present disclosure, moistureresistance reliability can be improved through increased mechanicalstrength of chip by adjusting the ratio (σte/σtd) of the standarddeviation of the internal electrodes 121 and 122 in each position to thestandard deviation of the thickness of the dielectric layer 111 in eachposition to satisfy 1.10≤σte/σtd≤1.35, and this will allow a multilayerceramic electronic component having excellent withstand voltage to beachieved.

When the ratio (σte/σtd) of the standard deviation of the internalelectrodes 121 and 122 in each position to the standard deviation of thethickness of the dielectric layer 111 in each position is less than1.10, the withstand voltage characteristics may be excellent, butmoisture resistance reliability may deteriorate in consequence ofreduced mechanical strength of the chip.

Meanwhile, when the ratio (σte/σtd) of the standard deviation of theinternal electrodes 121 and 122 in each position to the standarddeviation of the thickness of the dielectric layer 111 in each positionis greater than 1.35, the mechanical strength of the chip is high andthe moisture resistance reliability is not problematic, but thewithstand voltage characteristics may be lowered, thereby making thereliability an issue.

The standard deviation of thickness of the dielectric layer in eachposition is measured in a region of 20 μm×14 μm of a single dielectriclayer 111 in the L-T cross-section of the ceramic body, and is astandard deviation of a thickness of each dielectric layer in at least10 positions at an interval of 10 nm or less.

Additionally, the standard deviation of thickness of the first andsecond internal electrodes in each position is measured in a region of20 μm×14 μm of one internal electrode in the L-T cross-section of theceramic body, and may be a standard deviation of a thickness of eachinternal electrode in at least 10 positions at an interval of 10 nm orless.

Specifically, the standard deviation (σtd) of the standard deviation ofthe dielectric layer 111 in each position and the standard deviation(σte) of the internal electrodes 121 and 122 in each position may bemeasured by scanning an image of a length direction cross section of theceramic body 110 using an SEM as illustrated in FIG. 2.

For example, an average value may be calculated by measuring thicknessest₁ to t₁₀ of one dielectric layer 111 and t₁₁ to t₂₀ of one internalelectrode 121 extracted from the SEM-scanned image of the L-T directioncross-section of the ceramic body 110 cut in a central portion in thewidth direction (W) as shown in FIG. 2 at 10 positions at an equidistantinterval in the length direction as shown in FIGS. 3 and 4.

The equidistant interval is a distance (d) of 10 nm or less, and allowsmeasurements of the thicknesses (t₁ to t₁₀) at 10 positions of onedielectric layer 111 and that (t₁ to t₁₀) at 10 positions of oneinternal electrode 121.

The 10 positions of the one dielectric layer 111 and one internalelectrode 121 whose thicknesses are measured may be determined in acapacitance-forming portion, a region in which the internal electrodes121 and 122 overlap.

In an exemplary embodiment, the thicknesses (t₁ to t₁₀) were measured at10 positions of one dielectric layer 111 at the equidistant interval(d), but may be measured in at least 10 positions on the dielectriclayer at the equidistant interval of 10 nm or less, but are not limitedthereto.

Further, the thicknesses (t₁₁ to t₂₀) were measured at 10 positions ofone internal electrode 121 at the equidistant interval (d), but may bemeasured in at least 10 positions on the internal electrode at theequidistant interval of 10 nm or less, but are not limited thereto.

In order to calculate the standard deviation (σtd) of the thickness ofthe one dielectric layer 111 in each position, a value calculated bysubtracting an average thickness (td) of the dielectric layer 111 fromeach thickness of the t₁ to t₁₀ of the one dielectric layer 111 issquared. Resulting values calculated for all the t₁ to t₁₀ are averagedto calculate variance.

In order to calculate the standard deviation (σte) of the thickness ofthe one internal electrode 121 in each position, a value calculated bysubtracting an average thickness (te) of the internal electrode 121 fromeach thickness of the t₁₁ to t₂₀ of the one internal electrode 121 issquared. Resulting values calculated for all the t₁₁ to t₂₀ are averagedto calculate variance.

The square root of each variance is then taken to calculate the standarddeviation (σtd) of the thicknesses t₁ to t₁₀ of the one dielectric layer111 measured at the 10 positions and the standard deviation (σte) of thethicknesses t₁₁ to t₂₀ of the one internal electrode 121 measured at the10 positions.

The standard deviation (σtd) of the thicknesses t₁ to t₁₀ of the onedielectric layer 111 in each position and the standard deviations (σte)of the thicknesses t₁₁ to t₂₀ of the internal electrodes 121 and 122 ineach position are an index indicating differences in the thicknesses ofthe dielectric layer and the internal electrodes in each position andthe average thickness thereof, and are different from Ra, averageroughness at a center line.

That is, Ra, which is the average roughness of a center line, is a valueobtained by dividing the sum of areas of different parts by a surfaceroughness based on a virtual center line in an actual shape of oneinterface of the internal electrode by a predetermined length, and ithas a definition different from the standard deviation of thickness ofeach position of the internal electrode according to an exemplaryembodiment of the present disclosure, and there is a difference in themeasured values.

According to an exemplary embodiment, deterioration of moistureresistance reliability can be prevented and withstand voltagecharacteristics can be improved by appropriately adjusting the standarddeviations of the thicknesses of the dielectric layer and the internalelectrodes in each position.

That is, by finely adjusting the roughness of the internal electrodes,the interfacial bonding area between the internal electrodes and thedielectric may be increased. In addition, the withstand voltagecharacteristics of the multilayer ceramic capacitor may be increased bynot excessively increasing the roughness of the internal electrode.

A multilayer ceramic capacitor 100 according to an exemplary embodimentis a subminiaturized product with high capacity, and has the dielectriclayer 111 having a thickness of 0.4 μm or less and the first and secondinternal electrodes 121 and 122 of 0.41 μm or less, but is notnecessarily limited thereto.

In other words, as the multilayer ceramic capacitor 100 according to anexemplary embodiment is subminiaturized and has high capacity, thedielectric layers 111 and the first and second internal electrodes 121and 122 are formed to be thin films compared to those of conventionalproducts. Products to which such thin film dielectric layers andinternal electrodes are applied have an issue of deteriorations ofreliability due to shrinkage of the internal electrodes in the thicknessdirection during the sintering.

That is, conventional multilayer ceramic capacitors have a relativelythicker dielectric layer and internal electrodes compared to those ofthe multilayer ceramic capacitor according to an exemplary embodiment ofthe present disclosure. Accordingly, deteriorations of reliabilitycaused by the shrinkage in the thickness direction occurring during thesintering of the internal electrodes have not been a critical issue.

However, for a product to which thin film dielectric layers and internalelectrodes are applied as in an exemplary embodiment of the presentdisclosure, it is necessary to control the interfacial adhesion betweenthe internal electrodes and the dielectric layers in order to improvereliability.

To increase the interfacial adhesion between the internal electrodes andthe dielectric layers, a method of increasing the interfacial bondingarea between the internal electrode and the dielectric is demanding. Abonding area may be increased by finely adjusting the roughness of theinternal electrode.

However, when a roughness profile of the dielectric layers and theinternal electrodes is excessively adjusted, a side effect of reducedwithstand voltage characteristics of the multilayer ceramic capacitormay occur. Therefore, it is necessary to appropriately adjust theroughness of the dielectric layers and the internal electrodes so as toimprove the withstand voltage in addition to moisture resistancereliability.

Accordingly, it is necessary to appropriately adjust the roughness ofthe internal electrodes in a product to which thin film dielectric layerand the internal electrodes are applied, where the dielectric layer 111has a thickness of 0.4 μm or less and the first and second internalelectrodes 121 and 122 have a thickness of 0.41 μm or less afterplasticizing.

That is, in an exemplary embodiment, by adjusting the ratio (σte/σtd) ofthe standard deviation of the internal electrodes 121 and 122 in eachposition to the standard deviation of the thickness of the dielectriclayer 111 in each position to satisfy 1.10≤σte/σtd≤1.35, a multilayerceramic electronic components having excellent withstand voltagecharacteristics and improved moisture resistance reliability throughincreasing the mechanical strength of the chip even when the thicknessesof the dielectric layers 111 and the internal electrodes 121 and 122after plasticizing are 0.4 μm or less and 0.41 μm or less, respectively,can be accomplished.

However, the expression “thin film” does not mean that the thicknessesof the dielectric layers 111 and the first and second internalelectrodes 121 and 122 are 0.4 μm or less and 0.41 μm or less,respectively, but may be understood as being thinner than those ofconventional products.

Hereinafter, a method of manufacturing a multilayer ceramic capacitorfor accomplishing the feature of the present disclosure will bedescribed in more detail.

A method of manufacturing a multilayer ceramic electronic componentaccording to an exemplary embodiment involves preparing a ceramic greensheet comprising ceramic powder, forming an internal electrode patternwith a conductive paste comprising a conductive metal particle and anadditive on the ceramic green sheet, laminating a ceramic green sheet onwhich the internal electrode pattern is formed to form a ceramiclaminate, and plasticizing the ceramic laminate to form a ceramic bodycomprising a dielectric layer and an internal electrode. A ratio(σte/σtd) of the standard deviation of the internal electrodes in eachposition to the standard deviation of the thickness of the dielectriclayer in each position satisfies 1.10≤σte/σtd≤1.35.

According to an exemplary embodiment, a plurality of ceramic greensheets may be provided.

The ceramic green sheet may be prepared in the form of a sheet having athickness of several micrometers by mixing ceramic powder, a binder, asolvent, and the like, to prepare slurry and allowing the slurry to besubject to a doctor blade method. The ceramic green sheet may then besintered to be formed as a single dielectric layer 111 as illustrated inFIG. 2.

The thickness of the ceramic green sheet may be 0.6 μm or less, andthus, the thickness of the dielectric layer after plasticizing may be0.4 μm or less.

An internal electrode pattern may be formed by applying a conductivepaste for internal electrodes on the ceramic green sheet. The internalelectrode pattern may be formed by a screen-printing method or a gravureprinting method.

The conductive paste for internal electrodes may include a conductivemetal and an additive, and the additive may be at least one of non-metaland metal oxides.

The conductive metal may include nickel. The additive may include bariumtitanate or strontium titanate as the metal oxide.

A thickness of the internal electrode pattern may be 0.5 μm or less. Inthis regard, the thickness of the internal electrode after plasticizingmay be 0.41 μm or less.

The ceramic green sheets on which the internal electrode pattern isformed may then be laminated, pressed from the lamination direction, andcompressed. Accordingly, a ceramic laminate on which an internalelectrode pattern is formed may be prepared.

The ceramic laminate may be cut and chipped for each regioncorresponding to one capacitor.

In this case, the ceramic laminate may be cut so that one ends of theinternal electrode patterns are alternately exposed through a sidesurface thereof.

The chipped laminate may then be plasticized to prepare a ceramic bodyincluding a dielectric layer and internal electrodes.

The plasticization may be carried out in a reducing atmosphere. Inaddition, the plasticization may be carried out by adjusting atemperature increase rate. Although not limited, the temperatureincrease rate may be 30° C./60 s to 50° C./60 s at 700° C. or below.

According to an exemplary embodiment, a multilayer ceramic electroniccomponent can be achieved to have improved water resistance reliabilitythrough increased chip strength and have excellent withstand voltageresistance characteristics by adjusting the ratio (σte/σtd) of thestandard deviation of the internal electrodes 121 and 122 in eachposition to the standard deviation of the thickness of the dielectriclayer 111 in each position to satisfy 1.10≤σte/σtd≤1.35.

External electrodes may be formed to cover a side surface of the ceramicbody and be electrically connected to the internal electrodes exposed tothe side surface of the ceramic body. A plating layer of a metal such asnickel, tin, or the like, may be formed on a surface of the externalelectrode.

Hereinbelow, the present disclosure will be described in detail withreference to Examples and Comparative Examples.

Multilayer ceramic capacitors according to the Examples and ComparativeExamples were prepared according to the following methods.

Barium titanate powder, ethanol as an organic solvent, and polyvinylbutyral as a binder were mixed, ball milled to prepare ceramic slurry.The ceramic slurry was used to prepare a ceramic green sheet.

The conductive paste for internal electrodes containing nickel wasprinted on the ceramic green sheet to form internal electrodes, and agreen laminate, thus laminated, was subjected to isostatic pressing at apressure of 1,000 kgf/cm² at 85° C.

After cutting the compressed green laminate to prepare a green chip, thecut green chip was subjected to a debinding process at 230° C. for 60hours under an air atmosphere and was sintered at 1000° C. to prepare asintered chip. The sintering was carried out under a reducing atmosphereto prevent the internal electrodes from being oxidized, while settingthe reducing atmosphere to 10⁻¹¹ to 10⁻¹⁰ atm, which is lower thanNi/NiO equilibrium oxygen partial pressure.

A paste for external electrodes containing copper powder and glasspowder on an outside of the sintered chip was used to form the externalelectrodes, and a nickel-plating layer and a tin-plating layer wereformed on the external electrodes by electroplating.

According to the above method, a multilayer ceramic capacitor having asize of 0603 was prepared. The 0603 size may be 0.6 μm±0.1 μm and 0.3μm±0.1 μm in length and width, respectively. The characteristics of themultilayer ceramic capacitor were evaluated as follows.

Table 1 shows a comparison of electrode connectivity according to anaverage number of conductive metal particles in the thickness directionof the internal electrode pattern and determination results thereof,according to an exemplary embodiment of the present disclosure.

TABLE 1 Ratio of standard deviation of thickness of internal electrodesin each position to Judge reliability Withstand voltage standarddeviation of thickness Chip (No. of defects/ characteristics ofdielectric layer (σte/σtd) Strength (%) No. of samples) (comparison) 1*Less than 1.10 70 4/400 □ 2  1.10~1.20 80 0/400 ◯ 3  1.25~1.35 85 0/400◯ 4* 1.40 90 0/400 X [Evaluation] X: Bad, ◯: Good, ⊚: Very good*Comparative Example

Referring to Table 1, Sample 1 is a case in which the ratio (σte/σtd) ofthe standard deviation of the internal electrodes 121 and 122 in eachposition to the standard deviation of the thickness of the dielectriclayer 111 in each position is less than 1.10, indicating that thewithstand voltage characteristics are excellent but moisture resistancereliability may be deteriorated due to lowered chip mechanical strength.

Meanwhile, Sample 4 is a case in which the ratio (σte/σtd) of thestandard deviation of the internal electrodes 121 and 122 in eachposition to the standard deviation of the thickness of the dielectriclayer 111 in each position is 1.40, which exceeds 1.35. In this case,the moisture resistance reliability may not be problematic, but thewithstand voltage characteristics may deteriorate, thereby rising areliability issue.

On the other hand, Samples 2 and 3 are cases in which the numericalrange of the present disclosure is satisfied. This indicates that byadjusting the ratio (σte/σtd) of the standard deviation of the internalelectrodes 121 and 122 in each position to the standard deviation of thethickness of the dielectric layer 111 in each position to satisfy1.10≤σte/σtd≤1.35, a multilayer ceramic electronic component can beachieved to have improved water resistance reliability through increasedchip strength and have excellent withstand voltage resistancecharacteristics.

According to an exemplary embodiment of the present disclosure, moistureresistance reliability can be improved through increasing mechanicalstrength of the chip body, and the multilayer ceramic electroniccomponent having excellent withstand voltage characteristics may beimplemented by controlling the ratio (σte/σtd) of the standard deviationof thickness of the internal electrode in each position to the standarddeviation of the thickness of the dielectric layer in each position.

While exemplary embodiments have been shown and described above, it willbe apparent to those skilled in the art that modifications andvariations could be made without departing from the scope of the presentinvention as defined by the appended claims.

What is claimed is:
 1. A multilayer ceramic electronic component, comprising: a ceramic body comprising a dielectric layer; and first and second internal electrodes disposed inside the ceramic body and disposed to oppose each other with the dielectric layer interposed therebetween, wherein, when an average thickness of the dielectric layer is referred to as td and a standard deviation of a thickness of the dielectric layer in each position is referred to as σtd, while an average thickness of the first and second internal electrodes is referred to as to and a standard deviation of a thickness of a pre-determined region of any layer of the internal electrodes in each position is referred to as σte, a ratio (σte/σtd) of the standard deviation of the internal electrodes in each position to the standard deviation of the thickness of the dielectric layer in each position satisfies 1.10≤σte/σtd≤1.35.
 2. The multilayer ceramic electronic component of claim 1, wherein the average thickness of the dielectric layer and the first and second internal electrodes is an average thickness of the ceramic body in a length-thickness (L-T) direction cross-section cut in a central portion in a width (W) direction.
 3. The multilayer ceramic electronic component of claim 1, wherein the average thickness of the first and second internal electrodes is 0.41 μm or less.
 4. The multilayer ceramic electronic component of claim 1, wherein the average thickness of the dielectric layer is 0.4 μm or less.
 5. The multilayer ceramic electronic component of claim 1, wherein the standard deviation of thickness of the first and second internal electrodes in each position is measured in a region of 20 μm×14 μm of one of the first or second internal electrodes in a length-thickness direction (L-T) cross-section of the ceramic body, and is a standard deviation of a thickness of each of the first and second internal electrodes in at least 10 positions at an interval of 10 nm or less.
 6. The multilayer ceramic electronic component of claim 1, wherein the standard deviation of thickness of the dielectric layer in each position is measured in a region of 20 μm×14 μm of the dielectric layer in a length-thickness direction (L-T) cross-section of the ceramic body, and is a standard deviation of a thickness of the dielectric layer in at least 10 positions at an interval of 10 nm or less.
 7. The multilayer ceramic electronic component of claim 1, comprising at least 200 dielectric layers each interposing corresponding first and second internal electrodes.
 8. The multilayer ceramic electronic component of claim 1, wherein the ceramic body includes barium titanate.
 9. The multilayer ceramic electronic component of claim 1, wherein the first and second internal electrodes contain nickel.
 10. The multilayer ceramic electronic component of claim 1, wherein the multilayer ceramic electronic component has a length of 0.6 μm±0.1 μm and a width of 0.3 μm±0.1 μm.
 11. The multilayer ceramic electronic component of claim 1, further comprising external electrodes disposed on a surface of the ceramic body and include copper powder and glass powder.
 12. The multilayer ceramic electronic component of claim 11, wherein the external electrodes further include at least one of a nickel-plating layer and a tin-plating layer. 